Relay



July 17, 1934. A. s. GUERRIERI RELAY Filed Nov. 10, 1928 2 Sheets-Sheet l Fife/1 form- 1%fon/a Qttfj i/a 62 err/erz' July 17, 1934. A. a. GUERRIERI RELAY Filed Nov.

10, 1928 2 Sheets-Sheet 2 1/1 udiu:

IIIHHH Patented July 17, 1934 UNITED STATES PATENT OFFICE.

Application November 10, 1928, Serial No. 318,572 In Italy October 20, 1927 Claims.

Attempts that have been made to operate printing apparatuses on cables have always encountered difllculty with the sensitive relay. Even the recording siphon must in many cases 5 be aided by electronic amplifiers. Such amplifiers are also used in radiotelegraphy to render possible the writing. of the signals through the intermediary of a relay having moderate sensitivity.

Such amplifiers, as is well known, increase the useful currents as well as the transient, parasitic or disturbing currents. It is therefore always desirable to reduce their number whenever possible. Furthermore, a sensitive relay, in order to be useful in practice, must not be so complicated nor necessitate such amount of care as to render its use impracticable.

Thcobject of the present invention is to produce a relay which isnot only sensitive, but which is essentially practical. It is based on the principle that only a sharp'point or a sharp blade made of steel or of platinum can make a sure contact with the mercury covered with oil. The oil is' necessary to prevent the oxidation of the mercury and to wash the surface of the mercury as well as the steel or platinum; and only by cutting through the mass of mercury is it possible to throw aside the oil, which otherwise would im-- pede or even prevent the contact.

Naturally the points or blades must have a downward movement since the mercury must be contained in small holders, or containers.

' It should be noted that the mercury interposes a resistance to the penetration of the point, and w tends to throw the oil away from the points, and when the mercury closes, it throws away the oil from its mass. The oil also serves to dissolve in its mass all the impurities that may be present on the mercury and on the points. I

The use of platinum is preferable to steel because it is non-magnetic, and the use of a sharp blade is also preferable to a sharp point, since it has greater strength and is equivalent to a great number of sharp points.

The direction of the current must be from the platinum to the mercury, and by means of this arrangement the blade keeps its brightness, and even under the most disadvantageous operation it will only become slightly blunted in the course of time under the action of sparking.

It has been found that if the current passes from the mercury to the blade, some small grains of mercury are formed which are covered with oil,

and are valueless since they are neither noxious nor useful; the blade becomes dirty, without however losing its sharp contacts.

With my invention contact can be formed almost perfectly even after long, careless use, and even though the oil should have become thick and dense due to the action of dust and other impurities.

However, it is found that the oil burns with excessive intensity, and carbonizes, thus causing a bad odor. It is therefore advisable to shunt the receiving apparatus and to use a smaller intensity to avoid the sparks.

The invention will be better understood by the following description, taken with reference to the accompanying drawings showing one form of my invention by way of example, and in which:

Fig. 1 is a perspective view of a complete relay according to the present invention.

Fig. 2 shows a movable coil similar in construction to that employed in Fig. 1.

Fig. 2a is a part plan view of Fig. 2.

Fig. 3 is a schematic view of a telegraphic printing apparatus actuated according to the invenion.

Fig. 4 shows the relay accordingto my invention as applied to telegraphy.

Fig. 5 shows the same apparatus as applied to radio-telegraphy.

The principles outlined above can easily be applied to the usual Deprez-Darsouval movable telegraphic coil arranged in a strong magnetic field (magnets 11, 1/, and pole pieces 2:, x), as shown in Figs. 1 and 2. It will suffice to actuate a very light metallic balance a b c g, ,f, Fig. 1, instead of the siphon, and to convert the horizontal oscillations of the coil between the end pieces 1, 1 into vertical oscillations of this small balance.

The small blades of platinum soldered at the edge g-f of the balance are made to dip into the mercury containers m, and can be adjusted to different heights by means of micrometric screws 12', v".

The containers are fitted with a channel 1: which receives a thread or tape by means of which a rotating 'motion can be transmitted from the exterior. This arrangement is useful in case of very rapid signals when the incisions made in the mercury would not have time to close sufflciently rapidly, and it is therefore useful always to have new points of contact.

The connection of the balance top arm a with the coil is made by a connecting rod h. This rod embraces the top arm of the balance and is connected to the small tongue 1 by means of a pivot but arranged in an inverse position, is fitted on the lower part of the winding, with the difference however that the respective metallic piece u has only the bored stone, the counterstone being unnecessary in this case. In this lower part, in-- stead of the tongue 1', an insulating piece u" is provided, having a hole in its centre through which pass four threads of the multiplying conductor, as more fully described hereinafter.

The holes of the stones are traversed by steel needles which enter the central iron mass. The winding is held together by a suitable mastic and forms a frame with the pieces described above.

The small balance which consists of thin metallic blades, has ribs in all directions so that despite its extreme lightness, it nevertheless has suiiicient strength. I The small balance turns on its axis while the latter remains immovable, because since it is made of steel, its movements would be hampered by a strong magnetic field. For the same reason all other moving parts are preferably made from hard and non-magnetic metals, and it is for this additional reason that it is preferred to form the contacts as platinum blades instead of steel.

In addition to the coil, all other moving parts are supplied with hard stones.

The spindle c of the small balance rests on two notches made on a small support and is held by a spring d.

The wire on the coil is doubly wound, so that although it may be connected in series, it has a differential efiect. The four leads of the wire extend downward and penetrate into the base of the apparatus (Fig. 2).

These wire heads descend at first in a straight direction along the centre of rotation as shown by the dotted lines. They then separate and are fixed by suitable clamps to the ebonite disc 3 t (Fig. 2a).

Since these wires are thin, it is preferable not to fix them to the heads of the screws where they might be bent or cutjbut they are placed between two thin metallic plates held together by screws which also serve as the exterior attachments.

As is shown in Fig. 2, the disc s t is fixed on the lower part of the apparatus which rests on the support q r.

The small tongue oscillates between the screws 10 supported by the support q 1' which is similar to the lower support but is wider, to provide an opening through which the movement of the tongue can be observed, as well as the head of the frame, and, in part, also the polar extensions, m, x.

There are three containers, two of which, (m', m") are arranged at the two ends of the balance for the intermittent contacts, and one at the centre to ensure electric contact with the mass. This latter consists of a small thread of platinum soldered onto the small balance and passing over the mercury, its point being placed in the centre of rotation so as to impede the rotation, while the bending of the thread leaves sufilcient room for the edge of the container. The magnetic, field is strong, since it consists of two bundles of magnets 11, y of the same sign (see Fig. 1). One

of these bundles includes and protects the small balance and the containers. Fig. 1 shows the upper part of the apparatus, with the exception of the base, which is not important.

The relay forming the subject of the present invention can transform the very feeble current from a cable or a very feeble radio current (rectified) into a strong current sufdcient to actuate ordinary electro-magnets. For the Morse, Hughes, and Baudot apparatuses it is sufiicient to use only one container; for the Wheatstone apparatus two containers must be used.

As regards the registering siphon, the condi tions are different and some considerations are here necessary. As the siphon was constructed to work directly on a line, it would not appear to be convenient to work it with a relay; however the relay is more sensitive and can increase the efficiency of the cables. When the relay has converted the feeble current into a strong current, the siphon is no longer required since it is possible to register the signals in a much simpler way viz.: by inserting on the cable two relays in series instead of one. The resulting increased resistance is quite negligible in comparison to the advantage obtained.

The two relays will be arranged in such way that when for one relay the current is a working current, for the other relay it is a rest current. Springs already known facilitate the relative positions of inaction. In this way one of the relays will reproduce the positive output and the other will reproduce the negative output, viz.: the current which for one relay is a working current will maintain with greater energy the other relay in its rest position.

The relays can also be arranged in shunt (Fig. 4) by providing selectors, so that the positive current may find an easy path through one relay, while its passage is impeded through the other relay; the reverse condition maintains for the negative current. In this way the current is not subjected at its arrival to any large division as it is nearly all utilized to work only one relay. Even if a fraction of a contrary current is passing, it will tend to ensure a position of rest.

In Fig. 4 the selection is made, for reason of simplicity, by two galena crystals 0' and 0" arranged in opposite senses. It is'clear that the galena crystals may be replaced by other crystals, or by thermionic valves, or by other rectifiers.

The current coming from the cable L encounters on the left the first galena crystal, and on the right encounters the winding of the second galena crystal, thus passing, according to the polarity, either to one side or to the other.

In the first relay R the current enters at 2 and passes to the ground at 1, while in the second relay R the reverse operation takes place.

A large condenser K and a strong self-induction A through their mutual and synchronous reactions produce, when the current from the cable ceases, the return of each relay to its rest position, after it has been brought into its operable position by the current 01' the cable. In this way the relay may be very sensitive without the aid of springs or other contrasting medium.

The self induction A naturally absorbs a small portion of the principal current, and it reacts on the condenser K, and inversely with synchronizing effects through relays.

ance is used, it will receive through the relay only the reaction of the condenser.

An electric cell P sends current to one or the other of the two registering electromagnets B, 8",

If instead of the self induction a simple resistaccording to which one of the two small balances has made contact with the mercury 1n, and in this double connection, the whole system will occupy the diagonal of the bridge. In either case, two electromagnets E (Fig. 3) are actuated by the currents and they produce on a paper upper and lower dots, thus greatly facilitating the reading and helping the operator by the sounds which will allow him to take messages by hearing. In other words, at the receiving station, a reproduction of the transmitting station is obtained.

Fig. 3 shows one electro-magnet E, the other electromagnet, perfectly similar and symmetrical, being arranged behind the first one. The writers C are also two in number, one for each electromagnet, and are arranged within a short distance 0! each other. The same drawing also shows the cylinders J carrying the paper, and the piece M which takes the ink from the pot N. On the spindle of the piece M are mounted two toothed wheels arranged at a distance from each other, one in front and the other at the back of the pot N, these wheels each engaging a toothed wheel connected to the writers C which are thus made to rotate.

The levers carrying the writers C execute a slight movement only so that when moving downwards, they can receive the ink and the rotating movement. The lower spindle and the piece M are moved by a clock mechanism, while the spindle of the wheel 0 receives its movement from the spindle M as described above.

For radio applications the arrangement can be made in a simpler way as shown on Fig. 5'.

It is proposed to arrange the relay between the terminals, in place of the cuff, and to insert a rectifier g. In order to equalize the high peaks of the oscillating current a small condenser C is inserted in the wires of the relay. The remaining structure is identical .to the arrangement shown in Fig. 4. With this arrangement the relay obeys both strong and feeble currents without requiring any special adjustment, and is not influenced by the small waves which are so frequent. It also remains insensitive to many disturbances, especially when these are caused by variable currents directed in the same direction, which greatly disturb an ordinary telephone.

A cell unit P, in circuit with a strong resistance R. and with a small breaker T, serves to test locally the small repetition group. A cell Pa over a resistance R: actuates an ordinary relay 8, which sends the current of the cell P3 over a circuit L. The relay S has a shunt R: which together with the resistance R: reduces the spark in the mercury. i

It is preferable that the relay should have a slight tendency to remain in its rest position, and this action may be obtained by means of a spring. This rest condition could break the signals because the condenser K is actuated by impulses;

,however by shunting it, there will be a very slight prolongation of the current, suitable to maintain the working position when the receiver receives the lines of the Morse alphabet.

. fect including the new perioration of the paper strip for a new transmission and also the retransmission on a second cable.

What I claim is:

l. A sensitive electromagnetic telegraph relay ror operating a printing apparatus on cables, comprising a movable coil disposed in a vertical plane and movable about a vertical axis, a contact balance swingable about a horizontal axis, arms on said balance movable in vertical planes, means interconnecting said coil and said balance in such manner that the horizontal motion of said coil is translated into vertical motion of said balance, said arms of the contact balance having sharp points or blades, separate, rotatable containers associated one with each of said arms, and each container having a filling of oil-covered mercury therein, and having grooves on'the exterior thereof for cooperating with means for causing rota-' tion of the containers, that arm 0! the balance moved downwardly by the said coil piercing the oil and establishing conductive relation with the said mercury.

' 2. A sensitive electromagnetic telegraph relay for operating a printing apparatus on cables,

comprising a coil pivoted on a vertical axis for movement through a vertical plane, a contact balance pivoted on a horizontal axis for reciprocation in a vertical plane and having downwardly disposed arms at its ends terminating in sharply pointed arms or blades, the said balance bein connected with one terminal of a source of electrical supply, means interconnecting said coil and said balance in such manner that the horizontal movement of said coil is translated into vertical movement of said balance, separate, rotatable containers associated one with each of said arms and having a filling of oil-covered mercury therein, and having grooves on the exterior thereof for cooperating with means for rotating said containers, said containers each being connected to the other terminal of said source of supply, that one of said arms which is moved downwardly as an incident to movement of said coil piercing the oil and establishing conductive relation with said mercury, the source of supply being connected in such manner that the current flows from the arms to the mercury.

3. A sensitive electromagnetic relay, comprising a coil pivoted on a vertical axis for movement through a vertical plane, a contact balance pivoted on a horizontal axis for movement in a vertical plane and having downwardly disposed arms at its ends terminating in sharply pointed arms or blades, bearings for said balance, spring-biasing means for retaining said balance in said bearings, a support with which said spring is removably associated, so that upon removal of the spring the balance can be displaced from its bearings, the said balance being connected with one terminal of a source of electrical supply, means interconnecting said coil and said balance in such manner that the horizontal movement of said coil is translated into vertical movement of said balance. separate, rotatable containers associated one with each of said arms and having a filling of oil-covered mercury therein, and having grooves on the exterior thereof for cooperating with means for rotating said containers, said containers each being connected to the other terminal of said source of supply, that one of said arms which is moved downwardly as an incident. to movement of said coil piercing the oil and establishing conductive relation with said mercury, the source of supply beingconnected in such manner that the current ilows from the arms to the mercury.

4. A sensitive electromagnetic relay, comprising a coil pivoted on a vertical axis for movement through a vertical plane. a contact balance 15 or oil-covered mercury therein, and having grooves on the exterior thereof for cooperating with means for rotating said containers, said containers each being connected to the other terminal of said source of supply, that one of said arms which is moved downwardly as an incident to movement of said coil piercing the oil and establishing conductive relation with said mercury, the source of supply being connected in such manner that the current flows from the arms to the mercury.

ANTONIO BA'I'IAGLIA GUERRIERI. 

